KONSTANTIN CHRONOS,

The variances you see in the motherboard are from their order of release. A motherboard without the V identifier is normally the original board. If there is a change, improvement, or change of support. then it will get the next V designation. 

One of the prominent differences between the V4 motherboard and the prior 3 versions is the addition of Ivy Bridge & Sandy Bridge CPUs now being supported.

Now with interchangeability, normally the boards won't be interchangeable, as the risers and components may have also updated with the motherboard. So you may have a specific riser that is used for V2, and a completely different version of the riser for V4. With the R620 though the risers were changed for the V3 and V4 motherboards. So likely the V4 server would error with a V2 riser installed, and vice versa.

Let me know if this helps clarify things for you. 

Hi Chris,

Thanks for the reply - this information was very helpful. I was also wondering if, for example, you happen to have a V5 motherboard; would components that work in versions 1 through 4 work in a V5? I'm just trying to get a definite idea of which parts work with certain configurations.

Regards

It would be dependent on the changes for that version, but really anything 1-3 will not work on the devices beyond that version. So possibly a 4 will work with 5, but there is a chance it won't. So it is generally best practice to match the version of the hardware to their own versions.